Featured Articles from July 2016

Modeling Respiratory Depression Induced by Remifentanil and Propofol During Sedation and Analgesia Using a Continuous Noninvasive Measurement of pCO2

Adequate control of respiratory function under sedation-analgesia remains a challenge for the anesthesiologist because neither respiratory rate, tidal volume, pulse oximetry nor capnography are sensitive and specific enough measures. The present study uses a continuous transcutaneous noninvasive measure of CO2 which directly reflect the efficiency of ventilatory function as a pharmacodynamic endpoint of respiratory depression in response to propofol and remifentanil predicted concentrations to construct a mathematical model based on the data collected from 136 patients. The proposed pharmacodynamic model of respiratory depression integrates respiratory physiology principles and allows the clinician to estimate the level of CO2 as a function of propofol and remifentanil in patients sedated although breathing spontaneously. Such a model opens many possibilities to study in deeper detail respiratory response to anesthetic drugs or to be used as a learning tool to train anesthesiologist to perform safer sedation or to be used as an alert system while performing sedation-analgesia in real patients.